For what it's worth, my view on what you've told us agrees with others above, i.e., this paster was blinded by her investment in the match and perhaps unknowingly abused her power. In effect, she's failed her duty of care (though I don't know if that applies in religious organizations - does it, legally?).
She *ought* to be at least interested in how her actions have affected a member of her congregation. Realistically, passionate and persuasive people (I'm imagining her that way, is that off?), often have a gift for ignoring what they perceive as criticism. You obviously feel like you need 'back-up' to make your point.
I'm out of my depth with church business - but aren't pastors bound by some enforceable code of ethics, like counsellors, for example? (I don't mean the Bible... though I'd imagine there's reasonable guidance in there.) Is there a formal process you can use? Maybe talk to her in the presence of some kind of ombudsman?
In terms of the congregation... It's hard to move group-think, once a mood has taken hold. They might think you protest too much. They might twist what you say, to rationalize their trust in and affinity for your ex. Annoyingly, it's impossible to control what people do with what you put out.